Had a look at B&H regarding remote IRIS controls via the LANC port. Pretty slim. This change kind of sucks! I have always had separate controls for zoom and iris on each arm of the tripod for concerts and shows. If it is all on one remote you will be constantly taking one hand off the tripod arm to adjust the iris. Not cool unless there is a way to reliably split the signal to feed two controllers.
I often work the same way so am interested in this.
FWIW, have you sourced the options for the Panny zoom-iris lately. Varizooms offerings are the only option left I believe. Shame too, since the Manfrotto 521PF for controlling both focus and iris really has worked well for me. For zoom control on a tripod I have been using this:
http://www.manfrotto.com.br/remote-control-for-panasonic.html
You can find both on eBay if you are patient.